Extension cordsets are used in homes and businesses in order to connect appliances and electronic equipment to a source of power. Typically, cordsets are designed for indoor use and configured to carry 10 amperes or less of current. Other common heavy-duty cordsets are designed to provide power to tools or machinery. While the heavy-duty cordsets may be rated for outdoor use, the rating typically applies to the water resistance of the plastic jacketing on the cord and molded pieces without addressing the ability of the cordset connections to resist moisture.
A large proportion of outdoor cordsets are used in agricultural or construction settings where they provide power for operating a hand-held power tool such as a drill or circular saw. The extension cordsets in these settings allow a user to operate a tool at a remote distance from a power outlet. Thus, the user may move about a work site with the tool.
All extension cords intended for consumer use include one of two types of male plug: a two wire, non-grounded plug, or a three-wire, grounded plug. A three-wire plug and cord is generally configured and intended for devices utilizing a three-wire power cord, in which the third wire is used to ground certain parts of the device for safety reasons.
A danger exists, however, when a three-wire power cord from a device is plugged into a two-wire extension cord. In this situation, the third prong, which is the ground wire, is not connected. Therefore, most, if not all, consumer-type, two-wire extension cords are generally required to have an obstruction located on the face of a female receptacle that prevents a three-prong plug from being inserted therein. The obstruction is positioned such that the ground pin on the plug abuts the obstruction if an attempt to insert the three-wire plug into the two-wire receptacle is made.
Additionally, a three-prong receptacle typically includes an obstruction that prevents improper insertion of a three-prong plug upside-down into a reciprocal receptacle. If no obstruction was in place, the plug could be inserted into the receptacle upside-down, such that the ground pin was exposed. While the obstruction prevents the plug from being improperly inserted, it typically serves to alert a user that the plug needs to be rotated 180 degrees in order for proper insertion.
FIG. 1 illustrates a front view of a standard three-prong receptacle 2 with an obstruction 4. The obstruction 4 is required by Underwriters Laboratories (UL) in order to prevent improper insertion of a three-prong plug. The obstruction 4 includes a semi-circular face 6 that extends above the blade inserts, and generally aligned over the ground pin insert 8.
Setting aside the issue of improper insertion of a male plug into female receptacle, a male plug of a power tool, may also be susceptible to disconnecting from a female receptacle of an outdoor cordset. In order to prevent the male plug from disconnecting from the female receptacle, some users tie an end of the power tool cord and an end of the extension cordset in a knot. However, the act of physically tying the cords together may be annoying to some users. Additionally, the knotted connection may not always be secure. Further, tying the cords together inherently decreases the length of the extension.
Also, the interface between the extension cordset and the power tool cord may be exposed to water, for example, in a puddle, where the cord may short to ground. Alternatively, the male plug and the female receptacle may partially disengage from one another, thereby exposing live electrical contacts. As such, typical extension cordsets may present a danger to users and others as well as presenting a fire hazard. This same hazard can be found in cordsets for supplying power to recreational vehicles and electric motors, for example.
Specialty cordsets exist to ensure a secure, water resistant connection between the male plug and the female receptacle. However, these specialty cordsets typically include a unique, specifically designed male and female attachment to mate the two cords together. For instance, the common two- or three-prong plug that would be found on a 120 volt device for plugging into a standard wall outlet typically cannot be used in conjunction with the specialty cordsets, thereby limiting their practicality.